Hermetic seal for coke oven doors



w. T. BROWN HERMETIC SEAL FOR COKE OVEN DOORS Dec. 8, 1953 2 Sheets-Sheet 1.

Filed Sept. 26, 195.0

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'IIII INVENTOR. WalterTBrown l b I l 04. 7

. ATTORNEY 2 Sheets-Sheet 2 W. T. BROWN I-IERMETIC SEAL FDR COKE OVEN DOORS Dec. 8, 1953 Filed Sept. 26, 1950 I I I I x l I I l ATTORNEY n Lw w H/JT m 7% Walter T Brown Patented Dec. 8, 1953 UNITED "STATES BATPENT OFFICE .QHEEMETIQ SEALFORfCOKE.QYENJBQDRS .Walterlilruwn;RittsburghIPa. iAnlfl cationisentember 26, 1950, Serial No. 186,739

/ representinventions-relatesz tozzan attachle o 1 s. zoos 0,11 pitch; aspha1t,-asphaltites:or shale.

3 owrriaglcentury, numerous-types ofaseals ghave been devisedin" an :efiort to providea; satisyia t ryT-means {on-hermeticallysealing doors of sooke ovenseandi morerecently,.by product. coke cavenge-hut.- a p-gto the present timeisa completely i;satisiaetoifyssealghas not been attained.

By-product coke oven doors must be -closed tightl-y soithatnno'ia-ir,iwillaentersthe.oven chamdqdamage; the quality of Eooke,-an:d :gasand at eolgmoven; gases;-,wi11- -not; leak out. a, More 11103113; y providin gafhermeticz-sealabout e peripheralaedge portion of: the door, flair; is r ven e frqmienterinathemvenehamber which 111d;otherwise eauseisome of-the coke or;gases h .:;11 3gsen ia -1d: lowering rthe-lheating -value. W h6 11:i:.60183i$lhul nfig, athe ,;ashcontent of the rr ma nins mk -i .-increasedaan -ywh n the"g es are burned inside the :eoke-;;oven, -.,the tops are overheated .-an d considerableparbonz is formed on the .vzalls-;-and mopsaofithez-oven resulting in a .wr duction'of t eiyieldandouality ofelthe b rpro duets. By product-gcoke ovens. must be hermetilca ly sseale 1.12.0 gprevent tea es from e aping aamundith rdoors :becausathem are e nerally, is-

snited toys-the sho brickwork lan burn nausiine -,.warp ing of ;thev.eokenoven doors, ,door; jamhs and Mme h ing th -:b ckwork.tin plaee. .-F.'0r;me ysd rsfinhvzpr duo coke vensowere nia sandswet held. swenihriokworkhe end heat n flutes we .kept :away airmen th id r tand other coalf; char e .wasdr ppediinto-othe center paljt of the'pvento o prieven leek. or partia lv ookediendsnearl t ;doors. innaearlyiimp ovemen was ,to shrine the l;.ensi;f nes;n rerithe oven do rsd hrd ritorcok the whole coal charge, but this resulte d jnzexsoessiveiheaiins of,v th .-.do01:

d rs w .;;then improved lgytlining them with fire-brick and fix ending tl 1 m the oven .;to the end heatiingiflues. was followed bv anvimpr v sm ntsi nidesi n oiith doorsand door iambseAseomzno -sm an employed: in manysexistin aceke ;.ovensi nzor. ler ;-ticlose {th s ven ichamber sair-ti ht and e essiv h atin n .iwa ninssof th idiooriis-it pre ssth nd or n w h bar-sand wedeeiitsaaainstz h f o z the oo in ambe -sand lntet ner ph ral i .tsarolmd s'doonvrith clan-aria 9 a andoolse braizemixeene a ly-iefieo edsbv 2131 1 lfieatin rhisul ion burn, 1there y dilutin th 1 ak n 1 eases s ins ,the:ends...of vth lcoke Qutside. \Such-lutinghy .clayalsozhas the out- :standing disadvantage of requiring considerable ,itimeionmixingand handling of the lutingmaterial and involves considerable 7 cost f or applying such material. :Furthermore, Ithecoke-is, often- 10 times-t-contaminatedswith the high ash luting' -=ma-teria1.

--,,O ne ,ofwthe, most-recent improvements. in coke ,iovenz: doors -isi-theadevelopment vof ,a self-sealing door wherein thedooriis-oseateds against .a heavy aone piecedoastsimn jamb-iwithga machined face do; reoeivetthessealingsedge of the Ldoor. .The indoor is either: :of fsteelsor. cast iron. frame}, lined 'th fire-.briln on; preeeastiinsulating material. sAspring, steel sealing diaphragm is heldin-place against- .the..door lamb ,byseli-adjusting,spring- .loaded .plungers placed around thevperiphery of the sealing diaphragm. While:.such se1f=sealing aeoke ,oven; doors ,eonstituteva great improvement ,coverlvthe-iold design of. luted doors, and save conisiderablehtimefv and. eliminate the operating. cost tormixingiandhandling ofthe. lutingclamnever- ,theless, 311K511 selfesealingsdoorsarenot entirely .sati 'sfaotory. since they {do .7 notohermetically .seal by produettcokesoven.rjdoorsatsall times. The .wdoor jambs ;and ,the steel 'iknife edges .,become oma fipedaaftengperationg of .the coke. oven :and despite the adjustingimeans provided, it ,is-almost i1 nn0ssible ito adjustithe. spring plnngers, and to hold"thegknifeuedgesmin,place ,so othatvvtheyhmake rgnrglpe1r,nontaotiwithuthe maohinedsedges: of the cast iron door jambs.

lAn objectnfth priesentinvention is to provide iamovelsmeans. ionhermeticallyhsealing .byeprod- ..,not cokeiovengdoorsflwhichisidevoidofthedisad- 4&0 vantages of the above-mentioned .-commonly;used

.siealingimeans-rforisuch doorsF-and which is effecxiii 2 :3 lorovide 1a., hermetic seaLeven -WhBI1 such doors or door. iambsareswarped' or oracked,-also, .WhiQILis adantabletocokeioven doors of various existing designs aordnew designs.

; .A moresspecificoobjectwof 1 the presents-invention is to provide an attachment ,for hermetically sealing tcokeioven d.00rs which .may be readily sattachedito; oldidesiensi ofvdoors for .byroduct coke sevens :to .take the place, of other. seals apro- -755 hermetically \seal ;,the .:oven. and thus eliminate the tendency of contamination of the coke by high ash luting material.

Another object of the present invention is to provide an adapter or attachment which may be readily attached to present designs of self-sealing doors for icy-product coke ovens to provide an eliective hermetic seal when the knife edges are worn or the door or door jamb is cracked or warped so as to insure maintenance of the hermetic seal over a relatively long period of time despite high operating temperatures.

A still further object of the present invention is to provide an attachment for new designs of by-product coke oven doors, which attachment per se will constitute the sole means for hermetically sealing the door to prevent leakage of air or coke oven gases.

A still further object of the present invention is to provide a novel high temperature resistant sealing attachment for coke oven doors incorporating means for improving the heat resisting and elastic characteristics of the rubber far beyond that which is inherent in the rubber itself so as to increase its resistance to permanent deformation undcr pressure and heat and make it useful as an eiiective and reliable hermetic sealing means on coke oven doors which are subject to excessively high temperatures.

A more specific object of the present inven-v tion is to provide an attachment for hermetically sealing coke oven doors and th like, which attachment is in the form of a high temperature rubber, such as silicone, in the form of a hose or tubing and through which cooling fluid is adapted to how so as to maintain the rubber as well as the parts contacted thereby at relatively low temperatures so as to impart to the rubber amazingly improved heat stability, elastic characteristics and lower compression set values, thereby insuring a hermetic seal of the door despite high temperature operation of the oven and warping or the doors and door jambs.

A still further object of the present invention is to provide a high temperatur resistant rubber attachment in the form of hose or tubing which conducts a cooling fluid and which is dis posed in contact with the coke oven door and door jamb so as to cool them and prevent Warping and separation of a metal-to-metal contact in a self-sealing type of door and thereby considerably prolong the life of the hermetic seal and the efficiency of the cok oven.

Other objects and advantages of the present invention will be apparent from a study of the following description, taken with the accompanying drawings wherein:

ig. 1 is a transverse cross-sectional view of a coke oven door having secured thereto a hermetic sealing attachment involving the principles of the pr sent invention;

Fig. 2 is a plan view of the hermetic sealing attachment applied to the door shown in Fig. l, but shown removed from the door;

Fig. 3 is an enlarged fragmentary transverse cross-sectional view of a modified .form of door and sealing attachment for sealing the door against the door jamb;

Fig. i is an enlarged fragmentary cross-sectional view of still another modified form of hermetic sealing attachment for application on a coke oven door such as shown in Fig. 1;

Fig. 5 is a plan view of a cok oven door of the self-sealing type and including a sealing attachment embodying the principles of the present invention for insuring the hermetic seal Of.

the door at all times despite warping of the door or jambs, etc.;

Fig. 6 is a plan view of the attachment shown in Fig. 5 applied to a door of a sole-flue broad type of coke oven;

Fig. 7 is a side elevational View of the sealing attachment shown in Fig. 6 as applied to a broad sole-flue coke oven door, and

Figs. 8 to 15, inclusive, are enlarged cross-sectional views of various modifications of high temperature sealing attachments for coke oven doors embodying the present invention.

In the operation of by-product coke ovens and other carbonizing or gasification apparatus, the temperature at the doors or closures reaches as much as 800 F., particularly if the doors or closures are not hermetically sealed.

After considerable experimentation with varione high temperature resistant rubbers, such as silicone, for example, that sold under the trademark Silastic by the Dow-Corning (30., I find that even the best or these are unable to withstand the high temperatures encountered in coke oven doors, that is, temperatures in the range of about 300 F. to 860 F. While some improvement is obtained in the use of high temperature rubbers, the high temperatures encountered in coke ovens cause permanent set or deformation as a consequence of pressure and heat and loss of elasticity, thus making the sealing means inefiective to maintain a hermetic seal about the doors.

In accordance with the present invention, the high temperature rubber is shaped in the form a of a hose or tubing and cooling fluid is circulated therethrough so as to maintain the temperature below 300 F. Furthermore, because of the physical contact of the tubing with the door and door jamb, such door and jarnb are kept at reduced temperatures so as to prevent warping and loss of metal-to-metal contact between the door and iamb or between the door diaphragm and jamb such as is present in a self-sealing door of the spring plunger actuated type.

One of the outstandin high temperature rubbers found to be especially suitable for the purposes of the present invention is silicone, high temperature rubber, since it combines the stability of silicones and the elastic properties of ordinary rubber and will withstand continuous exposure to at least 300 F. for a long period of time, whereas organic rubbers Withstand only temperatures less than 200 F. Furthermore, silicone rubber will not soften or adhere to metal surfaces when hot, like organic rubbers and will not become hard and brittle and will retain its resiliency after long exposure to temperatures up to'SOO" F. However, long exposure to higher temperatures than 300 F. will cause a radual breakdown, due to oxidationwhich causes a white powder (silicon oxide) to appear on the surface of the rubber.

Silicone, high temperature rubber has a high thermal stability because it is a silicone polymer and not a synthetic or natural rubber and does not acquire this thermal stability from special compounding. The molecular structur of silicone rubber is built on a very strong silicon to oxygen linkage and continued exposure at 300 F. will not break down this silicon to oxygen bond. However, long exposure to temperatures exceeding 500' F. will cause a gradual breakdown by oxidation, causing a white powder (silicon oxide) to appear on the surface. Silicone rubber will not only stand high temperatures, but will also stand low tember'atures down to -40 F.

before becoming brittle. I

"Comparativetes'ts 'with silieon'e rubber and-organic rubber (GR-M specially compounded i or neat-ans oiI' resiStance) show that the organic silicone rubber has low compression =set values' up 't0400" Silieonahigh temp'erature rubber is matiefrom sil'icon'e polymers, which are semi-inorgan c materials. silicones are made from silicon tetrac'hloride'by replacing two or'more 'ofthe chlorine atoms with methyl groups. The pol-yd methyl siloxanes are made in various viscosities, the I longer 'the chain, the higher the viscosity.

The molecular structure of high temperature,

silicone 'rubber is built on a silicon-to-oxygnlinkage which has about 1- /2 times the bond strength of the carbon-to carbon linkage found in organic structure's. Greater bond strength combined with freedom from uns'a'tu'r'atibn accounts for the ihherent stability and resistance "tdheat. 7 7

Theoretically, similar polymers or high tempeiature rubberscan be made from other inorganic elements in "group l df the period c table, which includes: "carbon, silicon, titanium, germanium, zirconium, tin, "cerium, hafnium, lead and thorium. Polymers have been made from titanium, but "were found less stable than the silicone polymers. The present 'i'nveniron "contemplates the use of anyhigh temperature rubber made 'from"anysemi inorganic polymers.

Referring more particularly to Fig. 1 which shows a coke oven door assembly, numeral I denotes an opening forming .part of the oven chamber. A door frame or jamb 2 "of cast iron or Wrought iron surrounds the opening, and has integrally secured theretovertical beams or buckst'ays 3. Jamb 2 is corrugated to provide a shecession of shoulders and is lined interiorly with brickwork of suitable silica fire-brick 4 or the like. A door5 also of cast iron or wrought iron or other suitable metal is providedwith an. inner fire-brick lining 1 wh ch is held in place by inwardly turned flanges '6 of the door frame. The

door frame also has a flange 8 which provides a metal-to-metal contact with a'shoulder'ed portion of the door frame. However, this'contact is insufficient toprovide a su table hermetic seal for the door, therefore must be 'supplemented by a hermetic sealing means 9 "which embodies the principlesof the presentinve'ntion.

Sealing means 9 is in the form of 'a hose or Inibin'g made of hightemp'era'tu're resisting rubber, such as silicone, and havinga'n opening therethrough through which a suitable cooling flu d, such as Water, mineral or vegetable oil 'or' the like, may be circulated. The hose or tubing as shown more "clearly in Fig. 2"is in the "shape of. a rectangle which'extends about the'd'o'or perimeter to preventescape of coke oven gases to the outside or entry of outside air into the coke oven. It will be noted that this hose "or tubing is substituted for "the conventionally used 'luting 'clay which is'gener'allyapplied in the 'V-shaped -space between the door peripheral flange '8 and the wzonrrontingzportionbf the door jamb. accordance with "the present invention, such luting is eliminated and insteadameadily detachable hose hrtubin'g is emplo'y'ed. Incross se'ction, the hose or tubi-ng has 'asomewhat wedge-shapedwing 'or projection which is enclosed within a piece of an'gula'rly shaped strip'material til which-is detaehabl'y secured-to :thesperim'et'er of flange 8 of thecokeoven door by means-of screws I 1 or other suitable fastening means. The high temperature :"silicone rubber tubing m'a'ybeextruded or molded and 'rn aybe used i-niplain or laminated condition, f orexample, laminated'with fibreglass, fibreglass eloths, asbestos, asbestos cloth, aluminum foil'or other lie'at resisting, laminating orfillin'g material.

lnlet and outlet 'extensions *l 2 and [3, respec- "tively, are.=provided on the hightemperature'tub- 9 top'errnit the flow of cooling fluid through the tube, suches'watenoilor other suitable liquid, which inlet and outlet extensions are preferably provided with quick connective and disconnective shut-off eouplings 14 and 15, respectively, of well known type in wh ch to connect the coupling a plug is lpushed into the socket in order to open the line to flow of fluid, and to disconnect the coupling a slight'pull on the sleeve releases the plug and shuts off the supply end of the line. A well-known type-of sueh'coupling is 'thatknown as the Hansen push tite coupling manufactured and s'oldhy the Hansen Manufacturing Company, of Cleveland, Ohio. The specific construction of the "couplingxper'se'forms no part of thepresent invention. Of course, other types of couplings maybe usedi'nstead. Co'oling'fiuid, such as "water, from any suitablesource notshown) :iscirculated through tubinge in the direction indie ated bythe arrows at ajrate to keep the temperature of tubing fi below 30GE Tubing S ma'y be made of other high temperature rubber or rubber-like material other than silicone such as other semi-organic :poiymers made from elements in group 4 of the periodic table of inorganic elements, 'as described above, such as titanium lp'olyme'rs :made into high temperature r-ubbers.

An outstandingly important feature of the 'iiuid coo'led tubing 9' is that'yieldable contact is provided with the door-frame or jamb 2 thus presenting a'cooled surface and thereby reducing the'temperatu're'of the door frame sufiic'ientl'y to prevent-warping or cracking. Furthermore, even if the door ijamb were warped or cracked, the resiliency of tubing 9' would nevertheless insure a. hermetic seal since it would compensate for such warpingor cracking.

Fig. 3 shows a modified form of coke oven door assembly-in which the-door l6 is'prov'ided with a metaillic i ramework 1-1 extending about its periphery-and 'hawing -integrally connected with said trarrreworkarib air-flange l e. The door is internally lined with firebriok it which is exposed to the'coleeoven chamber. A door jamb 2G has'secured to its flash portion 21 'avertical beam or backstay 22. Door jamb 20 has an inwardly extending flange portion or ofiset 23 to provide a portion of door 'j'amb "2 8, a strip 25 of high temperature mistersuch as silicone, is provided which is'd'eta'chably secured torib it by means of metanic'stri'ps 26 and 'fa'stei'iin'g screws 27. The

strip 26 is shown as being of solid high temperature rubber which would be useful in coke ovens where excessively high temperatures of the door are not obtained, although it should be understood that if so desired, a channel may be formed centrally and throughout the length of the strip so as to circulate cooling fluid therethrough. Therefore, it will be seen that the strip 28 of high temperature rubber, such as silicone, is used in the place of luting clay.

Fig. a shows a modification of the coke oven door assembly which is identical in all respects to that shown in Fig. 1, hence the same reference numerals are employed to denote the same parts, with the exception that there is additionally provided a plurality of coil springs 28 which are guided by stems 29 so as to yieldingly urge strip portion Ilia and the enclosed rubber tubing 9 against the door jamb and thereby form, in effect, a plurality of spring actuated plungers for forcibly holding tubing 9 against the door jamb to insure maintenance of the hermetic seal. Strip portion itb forms part of a composite strip which is detachably secured to the periphery of the door.

Fig. shows a coke oven door assembly of the self-sealing type. A flanged door frame or iamb 38 is internally lined with fire-brick 3 I. An opening 32 which communicates with the interior of the coke oven is closed by means of a door 33 having marginal flange portions 3 5 which extend inwardly so as to hold a fire-brick lining 35 in place. Flanged members 35 are integrally secured to the flanges s4 and have mounted thereon spring actuated plungers 3? which push against inwardly bent flanges or knife edges 38 of a diaphragm 39 so as to provide metal-to-metal sealing contact with the door frame 36. Fasten-ed to the extremities of the inwardly extending flanges 38 are metallic strips it which surround a radially extending wing portion of the high temperature rubber tubing el. Tubing M is held in contact with the shoulder-forming surface of the door frame or jamb 3i Strips 4B are connected to diaphragm 39 by any suitable detachable fastening means, suchas screws or the like.

Tension adjusting means #2 are provided at the outer portions of the spring actuated plungers 31 so as to adjust the tension of the springs and thereby selectively obtain any amount of spring pressure against the extremities of the diaphragm 39 so as to tightly press tubing all as well as the flanges 38 against the door lamb and provide not only metal-to-metal but rubber-to-metal sealing contact and thereby insure a hermetic seal at all times. If, due to excessive heating of the door, the door iamb should become warped or cracked and the metallic contact between flange 3B and the jamb Ell is not continuously maintained throughout the entire perimetrical portion of the door, the rubber tubing 4! nevertheless does protemperatures to minimize warping and prevent cracking thereof.

Figs. 6 and 7 show a broad sole-flue type coke oven door in which tubing 4! is extended about the periphery of the coke oven door and show quick connecting and disconnecting couplings, such as 33 and it, for providing a detachable connection to a source of cooling fluid in order to maintain the temperature of the tubing and door jamb at safe value.

Figs. 8 to 15, inclusive, show various modifications in the cross-section of the high temperature rubber sealing means. Fig. 8 shows a form wherein the wing portion Ala, which is fastened within the metallic strip, extends radially of the cylindrical portion 41b. 'Fig. 9 shows a form in which the wing portion 4 lo extends in offset relation to portion Md. Fig. 10 shows a modification of sealing means wherein the wing portion 4 l e is adapted to be secured in the metallic strip, whereas a triangular or wedge-shaped portion 4|f is adapted to form a sealing contact with the door jamb as shown in Fig. 3. Fig. 11 shows a cross-section My of rectangular outline. Fig. 12 shows a hollow tubular portion 4 Ih having integrally extending therefrom a radially extending wing 4 l7. Fig. 13 shows a hollow tubular portion 1 lie having an enlarged inwardly projecting triangularly shaped part Mi so that even upon collapsing of the hose to the extent that part 4 li contacts the inner surface of the tube, a passage will nevertheless be maintained so as not to interrupt the flow of cooling fluid. An offset portion Mm is fastened to the detachable strip. Fig. 14 shows a still further modification of the high temperature rubber tubing 4 In which has a small pear-shaped instead of triangular opening Mo so as to minimize the tendency of closure of the fluid passageway upon collapsing of the tube and wherein a wedgeshaped wing Mp is provided for attachment to a strip such as 9 shown in Fig. 1. Fig. 15 shows a further modification in which tubing ilr has integral therewith a wedge-shaped wing 41s.

Likewise, other modifications of the high temperature rubber sealing tube or strip may be devised for providing a hermetic seal with the door frame or jamb and which is of a shape so as to minimize the tendency of stoppage of circulation of coolingfluid therethrough by collapsing the tubing.

Thus it will be seen that I have provided an efficient sealing means which may be substituted for luting material such as clay in old types of coke oven doors, thereby eliminating the time and costs required for handling and applying clay, or which may be used as a supplement to the metal-to-metal contact provided in self-sealing doors employing sealing diaphragms, or which may be relied upon exclusively as the sole sealing means in new types of doors; furthermore, I have provided a sealing means in the form of tubing of high temperature rubber, such as silicone, for maintaining the tubing at temperatures of less than 300 F. and thereby obtain substantially the elastic qualities of organic rubbers at low temperatures and low compression set values which are a measure of the resistance to per manent deformation under pressure and heat, and at the same time will provide a cooling surface which when yieldinglyv urged against the door frame or jamb will minimize warping and cracking thereof and thus provide a hermetic seal for long periods of time which will not fail despite high temperature operation of the coke oven.

While the hermetic sealing means for sealing has been described above as being useful for sealing coke oven doors, it is also useful for sealing closures in gas retorts, gas producers, water gas generators, shale retorts and other apparatus used to carbonize or gasify coal, oil, pitch, asphalt, asphaltities or shale and the like.

While I have illustrated and described certain specific embodiments of my invention, it will be understood that these are by way of illustration only, and that various changes and modifications may be made within the contemplation of my invention and within the scope of the following claims.

I claim: 7

1. The combination with a coke oven structure having an opening therein, a door frame surrounding said opening, a door for closing said opening by metal-to-metal contact with said door frame, and hermetic sealing means surrounding said door and engageable with a portion of the door frame adjoining said metal-tometal contacting portions, said hermetic sealing means comprising a tubing of high temperature rubber with a conduit therethrough for the passage of cooling fluid to improve the heat stability and elasticity of said rubber.

2. Apparatus recited in claim 1 wherein said door frame has a shoulder portion and wherein said door has a marginal flange portion which is adapted to seat against said shoulder portion, and wherein a detachable mounting means is provided to yieldingly seat said sealing means against a portion of said door frame closely adjacent to but exteriorly of the contacting portions of the door and door frame.

3. Apparatus recited in claim 1 together with a metallic strip having detachable securing means for detachably mounting said sealing means in place, said sealing means being in the form of tubing having a, radially extending wing, in cross-section, which is partially surrounded by and fastened to said metallic strip.

4. In a coke oven of the type having a horizontal open ended coking chamber, a metallic door frame at the end of the coking chamber and a, door having an outer peripheral flange adapted to provide metallic contact with an exterior flanged portion of said door frame, the improvement which comprises a tubing of high temperature silicone rubber extending about the periphery of said door peripheral flange and detachable fastening means for securing said tubing to said flange and for maintaining it in contact with a peripheral portion of the door frame in juxtaposition to and exteriorly of the metalto-metal contacting portions of the door flange and door frame, and a source of cooling liquid for circulation through the opening in said tubing for cooling the entire periphery of the door and door frame and for limiting the temperature of the silicone tubing to about 300 F. to improve the heat stability and elasticity of said rubber.

5. Apparatus recited in claim 4 wherein said fastening means for the tubing comprises an angular-shaped strip extending about the entire periphery of the door peripheral flange and includes a plurality of fastening means for detachably mounting said fastening means so as to maintain said tubing in contacting relationship with the door frame.

6. The combination with a coke oven structure having an opening therein and a door of the Gil self-sealing type for closing said opening, said door including a metallic sealing diaphragm whose periphery is adapted to provide yieldable metal-to-metal contact with the door frame, a strip of high temperature silicone rubber tubing secured immediately adjacent said periphery and in contacting relationship with the door frame exteriorly of the diaphragm and having a conduit for passing cooling liquid for insuring maintenance of a hermetic seal even when metalto-metal contact between the sealing diaphragm and the door frame does not exist throughout the entire periphery of the diaphragm.

7. In combination with a coke oven having a door frame interiorly lined with fire-brick and. having a door with peripherally extending flanges in metallic contact with the periphery of the door frame and being internally lined with firebrick, the improvement which comprises a tubing of high temperature resisting rubber through which a cooling liquid is adapted to pass, and spring actuated means for yieldably urging said tubing in hermetic sealing relationship with said periphery of the door frame externally of said metallic contacting parts.

8. Apparatus recited in claim 7 wherein said tubing is made of a high temperature resistant, rubber-like silicone.

9. Apparatus recited in claim 7 wherein said tubing has a radially extending flange and wherein detachable fastening means are provided to secure said tubing flange to the periphery of the door and wherein quick-acting, shut-off couplings are provided at the ends of said tubing to provide inlets and outlets which may be quickly connected to or disconnected from a source of cooling fluid.

WALTER T. BROWN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 725,746 Moore Apr. 21, 1903 871,421 Koppers Nov. 19, 1907 1,880,600 Umbel Oct. 4, 1932 1,966,202 Pfefferle July 10, 1934 2,385,627 Jones Sept. 25, 1945 2,395,852 Custer Mar. 5, 1946 FOREIGN PATENTS Number Country Date 500,074 Germany June 16, 1930 450,631 Great Britain July 22, 1936 576,206 Great Britain Mar. 22, 1946 OTHER REFERENCES Silicone Rubber, General Electric, 1949, 23 pages. 

1. THE COMBINATION WITH A COKE OVEN STRUCTURE HAVING AN OPENING THEREIN, A DOOR FRAME SURROUNDING SAID OPENING, A DOOR FOR CLOSING SAID OPENING BY METAL-TO-METAL CONTACT WITH SAID DOOR FRAME, AND HERMETIC SEALING MEANS SURROUNDING SAID DOOR AND ENGAGEABLE WITH A PORTION OF THE DOOR FRAME ADJOINING SAID METAL-TOMETAL CONTACTING PORTIONS, SAID HERMETIC SEALING MEANS COMPRISING A TUBING OF HIGH TEMPERATURE RUBBER WITH A CONDUIT THERETHROUGH FOR THE PASSAGE OF COOLING FLUID TO IMPROVE THE HEAT STABILITY AND ELASTICITY OF SAID RUBBER. 